British Poultry SciencePub Date : 2025-02-01Epub Date: 2024-09-09DOI: 10.1080/00071668.2024.2393960
B Ma, Y Zheng, S Liu, Y Qiu, X Xing, M Gao, Z Cao, X Luan
{"title":"Effect of goose-derived adiponectin peptide gADP3 on LPS-induced inflammatory injury in goose liver.","authors":"B Ma, Y Zheng, S Liu, Y Qiu, X Xing, M Gao, Z Cao, X Luan","doi":"10.1080/00071668.2024.2393960","DOIUrl":"10.1080/00071668.2024.2393960","url":null,"abstract":"<p><p>1. This study evaluated the effects and mechanisms of action of the peptide gADP3 on hepatic inflammatory injury induced by lipopolysaccharide (LPS).2. Hepatic inflammatory injury was induced in geese by intraperitoneal injection of LPS and gADP3, and the adiponectin receptor agonist AdipoRon (positive control) was used for potential amelioration. Serum inflammatory factor levels, liver function-related biochemical indicators and oxidative stress-related biochemical parameters in the liver tissues were determined. The expression levels of adiponectin and its receptors, inflammation and oxidative stress-related genes and key signalling molecules involved in adiponectin, inflammation and oxidative stress signalling pathways in liver tissues were detected.3. The peptide gADP3 alleviated inflammatory cell infiltration and hepatic inflammatory changes, reversed the decrease in serum albumin (ALB), total protein (TP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) content or activity induced by LPS and increased the activity of the antioxidant enzymes CAT (catalase), SOD (superoxide dismutase) and GSH-Px (glutathione peroxidase).4. The peptide gADP3 upregulated the expression of antioxidant enzyme-related genes GCLC, HO-1 and NQO1 in liver tissues, decreased the levels of inflammatory factors like TNF-α, IL-1β, IL-6, IFN-γ and TGF-β and reduced mRNA expression levels of inflammatory-related genes TNF-α, IL-1β, iNOS and TGF-β. Additionally, it increased the mRNA and protein expression levels of adiponectin and its receptors, as well as key molecules in the adiponectin signalling pathway like AMPK and PPARα. In addition, gADP3 reversed the changes in mRNA or protein expression of inflammatory and oxidative stress signalling pathway-related genes P38MAPK, NF-κBP65, TLR4 and Nrf2 in liver tissues caused by LPS treatment.5. In conclusion, goose-derived adiponectin peptide gADP3, similar to the adiponectin receptor agonist AdipoRon, attenuated LPS-induced hepatic inflammatory injury in geese.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"49-62"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142153163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
British Poultry SciencePub Date : 2025-02-01Epub Date: 2024-09-09DOI: 10.1080/00071668.2024.2394182
A Trentin, D J D Talamini, A Coldebella, A C Pedroso, T M A Gomes
{"title":"Technical and economic performance favours fully automated climate control broiler housing.","authors":"A Trentin, D J D Talamini, A Coldebella, A C Pedroso, T M A Gomes","doi":"10.1080/00071668.2024.2394182","DOIUrl":"10.1080/00071668.2024.2394182","url":null,"abstract":"<p><p>1. This study compared two broiler housing models with different technologies (conventional <i>versus</i> fully automated climate control) to verify their performance and carcass characteristics at slaughter, as well as the economics of production.2. A database regarding 20 443 flocks of heavy broilers produced in an integrated operation during the years 2020 and 2021, in eight Brazilian regions was used in the analysis. The dependent variables included feed conversion, average live weight gain, total and partial carcass condemnation and the total mortality. For economic analysis, the production cost of each technology including feed, labour, energy, heating and depreciation was calculated.3. The technology used in the broiler houses had a significant effect on the technical indicators which were positive for fully automated climate control in most geographical regions. One important exception was the effect on total and partial carcass condemnations, with better results seen for conventional housing. The total cost per ton of broiler meat delivered, deducting condemnation losses, was lower in the automated climate controlled housing compared to conventional housing.4. In conclusion, there was a reduction in broiler chicken production costs for birds raised in fully automated climate controlled housing, indicating better economic results for this model in Brazil.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"63-70"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142153165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D Miao, C Zhang, X Wu, Y Wang, V S Chowdhury, H Yang, Z Wang
{"title":"Transcriptomic analysis of long non-coding RNA and mRNA in pigeon squab pectoralis muscle development.","authors":"D Miao, C Zhang, X Wu, Y Wang, V S Chowdhury, H Yang, Z Wang","doi":"10.1080/00071668.2025.2451248","DOIUrl":"https://doi.org/10.1080/00071668.2025.2451248","url":null,"abstract":"<p><p>1. As one of the most widespread poultry species in the world, pigeons have been bred primarily for meat production due to their high nutritional value and good taste. Their breast muscle is an important economic product as it determines the yield and quality of meat from pigeons.2. Long non-coding RNA (lncRNA) plays an important role in transcription and post-transcriptional regulation, but research on the molecular mechanisms of this process in pectoral muscle development in pigeon squabs is lacking.3. Herein, RNA sequencing was used to analyse these mechanisms in pigeon squabs at different ages: 3(D3), 14 (D14) and 25 d (D25). A total of 56 169 differentially expressed (DE) lncRNA and 29 939 DE mRNA were identified among the three age groups, of which 483 were differentially co-expressed. A lncRNA-mRNA interaction network was constructed, and cis-trans identification, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed.4. The results showed that lncRNA affected muscle development through the cell cycle, cytoskeleton in muscle cells, motor proteins, extracellular matrix (ECM) receptor interaction, focal adhesion, and other signalling pathways. Five DE lncRNA and mRNA were selected (<i>LTCONS_00073284,LTCONS_00012834</i>, <i>LTCONS_00032767</i>, <i>LTCONS_00041298</i>, <i>LTCONS_00028245;TNNC1</i>, <i>XIRP1</i>, <i>PITX3</i>, <i>COL4A6</i>, and <i>TNNT3</i>). Their expression patterns were validated by reverse transcription-quantitative polymerase chain reaction (RT-QPCR), which were consistent with the high-through sequencing results.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-11"},"PeriodicalIF":1.6,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143063985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison of pathogenicity factors of avian pathogenic and extraintestinal pathogenic <i>Escherichia coli</i> isolates originating from broiler chickens.","authors":"S Sariçam İnce, A Ünal, M Akan","doi":"10.1080/00071668.2025.2451242","DOIUrl":"https://doi.org/10.1080/00071668.2025.2451242","url":null,"abstract":"<p><p>1. <i>E. coli</i> is an opportunist pathogen of animals, including food-producing ones and humans. Chickens may be a notable source of pathogenic and antimicrobial resistant <i>E. coli</i> for transmission to humans.2. This study compared virulence-associated genes (VGs) and antimicrobial resistance (AMR) in avian pathogenic <i>E. coli</i> (APEC) and extraintestinal pathogenic E. coli (ExPEC) isolates from broiler chickens, specifically APEC isolates in liver samples (<i>n</i> = 78) and ExPEC or non-ExPEC isolates in litter samples (<i>n</i> = 34). Virulence was evaluated by PCR for <i>feoB, hlyF, iroN, iss, iutA</i> and <i>ompT</i> genes, while AMR was evaluated by using antimicrobials from seven classes and detecting <i>bla<sub>SHV</sub>, bla<sub>TEM</sub>, bla<sub>OXA</sub>, qnrB, stcM, mrc1, mrc2, sul1</i> and <i>tetA</i> genes.3. The APEC isolates were found in 100% of livers, while ExPEC and non-ExPEC isolates were found in 44% and 56% of the litter samples. The predominant VG was <i>feoB</i> (100%), followed by <i>ompT</i> (63%), <i>iutA</i> (60%), <i>iss</i> (58%) and <i>hlyF</i> (43%). Surprisingly, <i>iroN, omp T</i> and <i>iutA</i> had higher prevalences in APEC isolates (85%, 96% and 96%, respectively) than in ExPEC isolates (73%, 87% and 73%, respectively) and non-ExPEC isolates (0% for all). The presence of all VG in 33% of isolates indicated high pathogenicity.4. The isolates were phenotypically resistant to ampicillin (93%), ceftazidime (72%) and nalidixic acid (82%). All APEC and ExPEC isolates (100%) were multidrug resistant (MDR), while 63% of non-ExPEC isolates were MDR. Genotypic AMR testing revealed that 53% and 52% of all isolates had <i>stcM</i> and <i>tetA</i>, respectively. No isolate was positive for <i>bla<sub>SHV</sub>, bla<sub>OXA</sub>, mrc1</i> or <i>mrc2</i>, which suggested the benefits of colistin for treating carbapenem-resistant enteric pathogens, due to the high resistance detected to meropenem (47%).5. Given the potential pathogenicity of <i>E. coli</i> isolates, improving biosecurity practices in chicken flocks should be prioritised to eliminate transmission to humans through the food chain.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143032301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y Xu, X Ji, X Chen, G Gui, T He, Y Xiao, L Lv, W Lyu
{"title":"Characterisation of <i>Proteus mirabilis</i> isolates from the poultry production chain in Zhejiang Province, China: antimicrobial resistance, virulence factors and genotypic profiling.","authors":"Y Xu, X Ji, X Chen, G Gui, T He, Y Xiao, L Lv, W Lyu","doi":"10.1080/00071668.2024.2436995","DOIUrl":"https://doi.org/10.1080/00071668.2024.2436995","url":null,"abstract":"<p><p>1. This study investigated antimicrobial resistance, virulence factors and genotypic profiling among <i>Proteus mirabilis</i> isolated from three sources (poultry farms, slaughterhouses and retail markets) in the poultry production chain in Zhejiang Province, China, to assess its potential risk to public health.2. A total of 112 <i>P. mirabilis</i> strains were isolated from 409 samples, including 35 from poultry farms, 35 from slaughterhouses and 42 from retail markets. Antimicrobial susceptibility was tested using 18 antimicrobials in 9 categories, in which 110 (98.2%) strains were considered multidrug-resistant (MDR). These strains carried numerous antimicrobial resistance genes, with the sulphonamide resistance gene (<i>sul1</i>) having the highest rate (100%) and the polymyxin resistance gene (<i>mcr-1</i>) the lowest (3.6%).3. These isolates were validated to carry virulence genes <i>pmfA</i>, <i>mrpA</i>, <i>atfC</i>, <i>rsbA</i>, <i>atfA</i>, <i>ureC</i> and <i>ucaA</i> with the high prevalence of 96.4, 92.9, 92.0, 85.7, 85.7, 57.1 and 46.4%, respectively. Genotyping results using the ERIC-PCR indicated that the genetic similarity of all the isolates was 68.6% to 100% which fell into 4 clusters.4. The <i>P. mirabilis</i> isolates from the slaughterhouses exhibited higher levels of antibiotic resistance and a more pronounced MDR phenomenon than those from poultry farms and retail markets. The proportion of isolates carrying the most commonly detected resistant and virulence genes was higher in samples from poultry farms and slaughterhouses as opposed to retail markets. Importantly, there was genetic similarity and heterogeneity among <i>P. mirabilis</i> isolates from the three sources and genotypic diversity was the highest among isolates from retail markets, followed by slaughterhouses and poultry farms.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143032299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C Nel, A Gilmour, P Muvhali, S Cloete, M Kekana, A Engelbrecht
{"title":"Evaluating the genetic components of growth in ostriches with multi-trait and random regression models.","authors":"C Nel, A Gilmour, P Muvhali, S Cloete, M Kekana, A Engelbrecht","doi":"10.1080/00071668.2024.2442697","DOIUrl":"https://doi.org/10.1080/00071668.2024.2442697","url":null,"abstract":"<p><p>1. The heritability (h<sup>2</sup>) of liveweight (LW) in ostriches can be highly variable, depending on age at recording. The objective of this study was to consider random regression (RR) as an alternative to the multi-trait (MT) structure for the analysis of repeated measures of LW.2. The data included 74 683 LW phenotypes recorded from 10 052 birds aged between 20 and 410 days (d) of age. Statistical analysis included single trait (ST), MT and RR analysis in a linear mixed model framework using the ASREML V4.2 software.3. For ST and MT, six traits were defined to represent LW at 28, 77, 150, 230, 300 and 365 d of age. Random variance components included direct genetic and maternal permanent environment (PE) effects. A MT analysis including all six traits converged.4. For RR, the data was transformed (LW + 10)<sup>-0.5</sup> due to difficulty in dealing with large scale effects. The final RR model fitted direct genetic and animal PE components as third degree Legendre polynomials and heterogeneous residuals.5. The h<sup>2</sup> estimates was in agreement across analysis, ranging from moderate (0.16-0.20) for W28 to high (0.41-0.51) for W230 to W365. Importantly, the genetic relationship between LW recorded as a chick and juvenile was only moderate (~0.35 to 0.55). The correlations between RR and MT EBVs for the six traits were 0.85, 0.54, 0.65, 0.75, 0.83 and 0.91, showing a considerable level of re-ranking.6. This study reaffirmed age dependent genetic variation when determining LW in ostriches. The RR structure was useful for overcoming the dimension problem of MT analysis, but was susceptible to scale effects present in the data, despite transformation. It remains unknown whether the need for cubic terms reflected scale or animal effects.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-10"},"PeriodicalIF":1.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143000556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O Madacussengua, A R Mendes, A M Almeida, M Lordelo
{"title":"Effects of using microalgae in poultry diets on the production and quality of meat and eggs: a review.","authors":"O Madacussengua, A R Mendes, A M Almeida, M Lordelo","doi":"10.1080/00071668.2024.2420330","DOIUrl":"https://doi.org/10.1080/00071668.2024.2420330","url":null,"abstract":"<p><p>1. This review was conducted to examine the nutritional composition of microalgae and their effects as a feed ingredient in poultry diets, delving into their influence on the production and quality of meat and eggs. Data collection focused on peer-reviewed scientific articles, with no limitation on the temporal horizon.2. Regarding nutritional composition, the collected papers indicated that certain microalgae species have a rich nutritional composition, with approximately 50% of their biomass composed of proteins. They contain a high concentration of EPA and DHA, important fatty acids that are found in low concentrations in conventional feedstuffs, and the presence of carotenoids such as beta-carotene.3. Incorporating microalgae into the diet of poultry can improve performance variables, such as mortality, live weight and feed conversion rate. It promotes benefits in meat and egg quality, with reduced cholesterol, increased EPA and DHA, intensified colour and higher concentration of carotenoids.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-17"},"PeriodicalIF":1.6,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M Van der Eycken, K Hertogs, S Willems, M Heyndrickx, G Rasschaert
{"title":"A comparison of immersion-based and spray-based crate washing systems on the impact of <i>Campylobacter</i> spp. reduction.","authors":"M Van der Eycken, K Hertogs, S Willems, M Heyndrickx, G Rasschaert","doi":"10.1080/00071668.2024.2435013","DOIUrl":"https://doi.org/10.1080/00071668.2024.2435013","url":null,"abstract":"<p><p>1.During transport of broilers from farms to slaughterhouses, the interior of crates may become contaminated with faeces. When these crates are not cleaned and disinfected adequately, they pose a potential risk for the dissemination of pathogens, including <i>Campylobacter</i> spp., between slaughterhouses and farms.2. The aim of the trial was to compare the efficacy of immersion-based crate washing systems with a spray-based washing system in reducing <i>Campylobacter</i> spp. Therefore, the crate washing systems in two slaughterhouses were sampled. In one of these two slaughterhouses, the immersion-based crate washing system was replaced by a new spray-based system which was sampled. Samples were collected from the slaughterhouse equipment, the crate washing system as well as from the crates both before and after cleaning and disinfection (C&D). All samples were screened for the presence of <i>Campylobacter</i> spp.; water and crate samples were used for enumeration. Molecular typing was performed to investigate the source and routes of contamination.3. In all cases, crates were contaminated with <i>Campylobacter</i> spp. prior to washing. However, only the spray-based system achieved a significant reduction after C&D Molecular typing revealed that the same strains were present on the crates after C&D as before cleaning. Additionally, crates could become contaminated by previously cleaned crates <i>via</i> wash water in the immersion-based crate washing system.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Are slow-growing broiler chickens actually better for animal welfare? Shining light on a poultry welfare concern using a farm-scale economic model.","authors":"I Khire, R Ryba","doi":"10.1080/00071668.2024.2432926","DOIUrl":"https://doi.org/10.1080/00071668.2024.2432926","url":null,"abstract":"<p><p>1. It remains unclear whether slow-growing broilers actually represent an overall animal welfare improvement - a major knowledge gap for policymakers and animal welfare NGOs. This paper addresses this knowledge gap by using an economic model to produce an all-things-considered estimate of the welfare effects of slow-growing genotypes. A quantitative end-point welfare metric that accounts for welfare challenges throughout the production cycle used the Pain-Track method from the Cumulative Pain Framework.2. Longer lifespans of slow-growing broilers (relative to fast-growing broilers) typically caused an increase in the time spent in low-intensity negative affective states. However, despite the additional broilers being farmed and their longer growth period, switching to slow-growing genotypes caused a decrease in higher-intensity negative affective states - a major win for welfare.3. These results can be used to alleviate consumer and producer concerns that any transition causes a welfare risk and provide an optimistic understanding of the overall welfare impact of transitioning to slow-growing broilers.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-9"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G L Liu, M L Qiao, H C Zhang, C H Xie, X Y Cao, J Zhou, J Yu, R H Nie, Z X Meng, R Q Song, Y Wang, J L Ren, Y J Zhao, J Q Sun, R W Fan, G J Shang, S Niu, W X Tian
{"title":"Avian pathogenic <i>Escherichia coli</i> alters complement gene expression in chicken erythrocytes.","authors":"G L Liu, M L Qiao, H C Zhang, C H Xie, X Y Cao, J Zhou, J Yu, R H Nie, Z X Meng, R Q Song, Y Wang, J L Ren, Y J Zhao, J Q Sun, R W Fan, G J Shang, S Niu, W X Tian","doi":"10.1080/00071668.2024.2435618","DOIUrl":"https://doi.org/10.1080/00071668.2024.2435618","url":null,"abstract":"<p><p>1. Avian <i>Escherichia coli</i> (<i>E. coli</i>) causes significant losses in livestock by inducing morbidity and mortality. Erythrocytes, the most abundant in blood, possess dual functions of oxygen transportation and immune regulation. In recent years, the interaction between erythrocytes and the complement system has gradually become a focal point of study. However, the transcription dynamics of the complement system in chicken erythrocytes post-<i>E. coli</i> invasion remains unclear.2. In this study, chicken erythrocytes and <i>E. coli</i> were co-cultured for 0.25-2 h to assess adhesion, analysed by indirect immunofluorescence (IIF) and scanning electron microscopy (SEM). Quantitative real-time PCR (qRT-PCR) examined differential expression of complement genes (<i>CD93, C1q, C1s, C2, C3, C3AR1, C4, C4A, C5, C5AR1, C6, C7, C8G, CFI, MBL</i>) <i>in vitro</i> using erythrocytes at 0.25-2 h and in <i>vivo</i> using chicks at 1, 3 and 7 d post-<i>E. coli</i> infection.3. <i>E. coli</i> adheres to chicken erythrocytes, as observed using IF and SEM. Gene expression analysis revealed early downregulation of C4, C4A, MBL and late upregulation of CD93, C1q, C1s, C3, C3AR1, C5AR1, C6, with C5, C7, C8G downregulated at 7 dpi. C2 expression varied at each time point.4. This study first showed <i>E. coli</i> adhering to erythrocytes, which activated complement genes rapidly. <i>In vivo</i> recovery from chickens with colibacillosis favours classical pathway activation, while lectin pathway may be inhibited, suggesting early immune down-regulation.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-8"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142930677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}